Sterns lost their diamond customer services

I bought my engagement ring. After an incident I had to replace it. I went to the same sterns to buy the same ring and resizing to the sane as the first ring. I was advised its not allowed. The consultant consulted her manager at the back to confirm it could not be done. My old broken ring could also not be repaired and they cannnot put nor help me back into the same position before my incident. Although they were cery friendly and helpful with my first purchase. How can the processes change and show clients away while helping them out in the first place. They should have referred me away with my first purchase. I will not use Sterns again nor have i received the sms back to state my old ring is back at the for collection which they can not repair.